// var s = (function() {
//     var undefined = "";
//     return JSON.stringify({a:1,b:2,c:undefined});
// })();

/////////////////////////////

// 
var hash = {
  "name" : "boda",
  "email" : undefined,
  "country" : "africa"
};

var string = JSON.stringify(hash);

console.log(string);


var s = (function() {
    var undefined = "";
    return JSON.stringify({a:1,b:2,c:undefined});
})();

console.log(s);